This book provides an in-depth analysis and examination of the De musica treatise attributed to one Aribo, written sometime between the late eleventh and early twelfth centuries. The author is associate professor of musicology at the Eastman School of Music, and she publishes extensively in the areas of medieval musical thought and post-Byzantine music iconography. In the prologue, the challenges and historical assumptions regarding this particularly challenging treatise are examined. The extraordinary terminology and imagery used in the manuscript are not found elsewhere; it is a highly personal and peculiar language that is quite unusual and unique for eleventh- century musical thought; indeed, the complex imagery and conceptualization of terms and associations makes one wonder whether the treatise should be taken seriously at all. It is here that Ilnitchi attempts to provide as much evaluation, interpretation, and investigation as possible, in order to glean as much information about why this treatise has been given only passing attention by music scholars thus far. As such, this book is the first major attempt to provide meaning and documentation on this obscure and difficult-to- understand musical treatise.

Ilnitchi's assertion is that engaging the text as an historical document is important, and that it should be examined in light of its theoretical predecessors and its eleventh-century cultural milieu; therefore, some type of understanding of the music-theoretical content will develop from this study. She has divided her research on this treatise into two parts. Part I, which she dubs "more positivistic" in nature, looks at textual transmission and the musical examples in Aribo's De musica. Chapter 1 examines the manuscript sources, of which there are more than a dozen, most from the twelfth century. Most of the sources are fragments, with two complete surviving manuscripts among them. The majority of the sources cited have only recently been found, thus making Smits van Waesberghe's 1951 edition of this treatise obsolete. After discussing the manuscript sources, Ilnitchi attempts to follow the transmission history, discussing the full-text recension (with particular emphasis on the role of the libellus), as well as how text from Aribo's treatise found its way into other music treatises, especially the anonymous Quaestiones in musica, and Jacques of Liege's Speculum musicae of the 1320's. Ilnitchi then discusses Section C and the figura circularis and its four transmission contexts, along with some comments on the last two chapters of the treatise, which stand out due to their stylistic and rhetorical differences from the rest of the content. Some interesting charts and figures are included in this chapter, and some assumptions regarding the actual location of composition and identity of the author based on the examination of the sources is provided.

Chapter 2 deals with all the chant examples contained in the treatise. Ilnitchi comments that Aribo cites over two dozen chants, but they appear in only a small number of chapters that deal with three main topics: modality, intervals, and references to Guidonian musical theory. Each topic is dealt with in depth, comparing some of the chant references to other musical treatises, especially Wilhelm of Hirsau's De musica. An extensive discussion of the Guidonian chant material is also given. Ilnitchi comes to the conclusion from the examination of the chant material in the treatise, that Aribo's use of chant examples was very distinctive. He did not find contradictions between the melodic design of a chant and theoretical knowledge, which marks him as an exception among the writers of music theory during his time period. His tone and style indicate that his treatise was not a pedagogical text for beginners, but written for a knowledgeable and musically-versed audience.

Part II, then, focuses on the music-theoretical, philosophical, and theological aspects of Aribo's treatise. Chapter 3 examines the philosophical background of the work, playing with the doctrines of rhetoric, logic, and natura. Ilnitchi spends a lot of time discussing Aribo's introduction to the treatise from a rhetorical point of view, pointing out that Aribo's style goes well beyond the prescribed principles and indicates that the text which follows is deeper than surface appearances. In fact, the dedicatory letter is a perfect example of an exordium or principium, generally regarded as a passage that assists the reader to prepare their mind for the rest of the speech. Three major rhetorical tropes are also incorporated in the introduction, which are followed throughout the treatise. These are palaemon, theorema, and ludus. Ilnitchi provides a fairly in depth exploration of these tropes, and then moves into a description of the treatise itself. While the treatise is divided into 101 unnumbered chapters, the focus of the book is based on Chapters 2-15, which describes Aribo's caprea diagram as a visual construct and alternative to the quadripartita figura. It is this portion of the treatise that is Aribo's unique contribution to both eleventh-century and medieval music-theoretical literature. Ilnitchi then focuses on different categories of reasoning within Aribo's treatise, examining arguments such as Aribo's discussion of the two-octave ambitus of the monochord, for example, providing some parallels from Boethius and Martianus Capella. Finally, the concept of natura is examined, and specific instances of Aribo's obsession with certain sections of Guido of Arezzo's Micrologus are explicated.

Chapter 4, then, involves a philosophical examination of the order and treatment of various theoretical topics found in the treatise, and Ilnitchi determines that the theoretical model portrayed is very similar to that of other South-German intellectual manuscripts of the late eleventh century. Various examinations of Aribo's discussions regarding his caprea and how much better it is than the traditional quaripartita, the monochord, the tetrachords, the species of consonance, the chordae, and the modes are provided by Ilnitchi, along with accompanying charts and illustrations and comparisons with other contemporary music theorists. Chapter 5 goes on to examine Aribo's treatise at the theological level, especially his caprea concept, the figura circularis, and the mysteria vitae Christi tetrachords.

In the epilogue, Ilnitchi argues that Aribo's treatise has multiple layers, both intertwining and overlapping, in its approach and in the topics and materials that it discusses. All of these layers, built on rhetoric, the discursive method, metaphor, and theoretical content complement each other. Together, they provide a very complex imagery and vision of music theory in the late eleventh century that is built on Eriugenian overtones and is a type of embodiment of contemporary medieval theology. Again, Ilnitchi provides some fascinating charts to illustrate these complex relationships, moving towards a discussion of Neoplatonistic tendencies in Aribo's work, comparing his musico- theoretical model to that of John Scot Eruigena's fourfold division of nature.

This critical edition contains extensive notes after each chapter, and also contains a large bibliography of resources, along with an index. I found this book to be highly informative, and the author has a wide range of knowledge and experience in the cultural and theological backgrounds related to this particular treatise. As a result, some very interesting insights and objective formulations for understanding this particularly complex and misunderstood treatise are examined and researched. The author's use of charts and illustrations are of especial help when trying to follow her line of reasoning and direction when especially intriguing suppositions are proposed. In the end, the author does an excellent job of maintaining perspective and objectivity as she attempts to assist the reader in general, and musicologists specifically, in the understanding of this marginalized music treatise.